Fluctuation-damping means for rotatable members.



H. W. NICHOLS. ELUCTUATION DAMPING MEANS FOR ROTATABLE MEMBERS.

APPLICATION FILED MAR. 22. 1915.

1,230,205. Patented June 19, 1917.

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APPLICATION FILED MAI'I. 22, I915.

Patented June 19, 1917.

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I Wmesses:

UNITED STATES PATENT. OFFICE.

HAROLD WILLIAM NICHOLS, OF EAST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

FLUCTUATION-DAMPING MEANS FOR ROTATABLE MEMBERS.

Patented June 19, 1917.

7 Application filed March 22, 1915. Serial No. 16,000.

To all whom it may concern:

Be it known that I, HAROLD W. a citizen of the United States, East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Fluctuation-Damping Means for Rotatable Members, of which the following is a full, clear, concise, and exact description.

This invention relates to means ing out fluctuations in tating member.

Fly-wheels containing liquids have been used for this purpose, and the general object of the invention is to render a fly-wheel of this type more efficient as a means for Nrcnons, residing at for dampthe speed of a rodamping out fluctuations in speed and at the same time provide an eas1 structure.

the present lnvention in a y assembled To this end, broad aspect consists in providing in a unitary flyheel chamber containing a liquid very large surfaces with which the liquid can frictionally engage and yet by which it will not be positively impeded in its direction of flow as the fluctuations in the speed of the fly-wheel take place. According to the present invention these large frictional surfaces between the liquid and the flywheel structure are obtained by providing in the liquid chamber sectional walls arranged substantially parallel to the path of movement of the chamber. These sectional walls may form planes or partitions in the liquidchamber perpendicular to the axis of the flyheel or they may be arranged concentrically and coaxial with the fly-wheel. In neither case do they form completely separated compartments as each partition or wall is provided with one or more openings through which the fluid in the chamber may pass from one compartment to another. In the preferred form of the invention hereinafter described the sectional walls in the liquid chamber are radial or perpendicular to the fly-wheel axis.

A very advantageous feature of this invention is the ease with which the entire structure can be assembled and the fluid chamber filled. By providing openings in each wall or partition so that the fluid in the chamber may flow from one compartment to another, the necessity of filling each compartment individually is eliminated.

In the improved structure herein disclosed the container is in reality a unitary chamher and all of its sections may be filled in one operation.

' The invention is particularly useful in connection with printing telegraph apparatus although it is not limited to that particular field.

The invention will be fully understood from the following description taken in connedtion with the accompanying drawings, in

which Figure 1 1s a side elevation, partly in section, showing a fly-wheel having the invention embodied therein mounted on a shaft with certain devices used in connection with printing telegraph systems; Fig. 2 is a fragmentary sectional elevation on the line 2-2 of Fig. 1; Fig. 3 is a sectional elevation showing a modified form of flywheel embodying the invention; and Fig. 4 is a fragmentary sectional elevation on the line l4 of Fig. 3.

Referring to Fig. 1, the preferred form of the invention is shown as applied to the shaft 5 of a synchronous motor 6 which drives a brush distributer 7 of a kind well known in the printing telegraph art. It is to be understood, however, that the present invention is not limited to use in connection with printing telegraph apparatus.

In Figs. 1 and 2 the fly-wheel embodying the preferred form of the invention is shown as comprising a hub portion 9, a web portion 10 and a hollow rim portion, the form of all of these parts being obvious from the drawings. As shown, the inner wall 11 and one of the end walls 12 of the hollow rim portion are made integral with the hub and the spoke portions of the wheel; and the outer wall 13 and the other end wall 14 of said hollow rim portion are formed by a casing which may be shrunk upon or otherwise suitably secured to the portions 11 and 12. The hub 9 may be secured to the shaft 5 in any suitable manner as by a key 16 and a nut 17.

Within the chamber formed by the hollow rim portion of the fly-wheel are sectional walls which, in the embodiment of the invention shown in Figs. 1 and 2, are radial and consist of a plurality of flat rings '19 which are held apart by spacing rings 20.

The chamber in which the rings 19 form such as mercury which can be introduced and it has been found that a ratio of about through holes which are shown as closed by four to one is highly satisfactory in connecplugs 22. The rings 19 are either made to fit tion with the printing telegraph apparatus the chamber rather loosely or have holes in to which the mvention is herein shown as them to allow free passage of the liquid applied. It is, of course, des 'irable to make throughout the chamber during the filling the friction between the liquid and the suroperation. faces with which it engages as large as pos- In the form of the invention illustrated. sible. To this end, as many sectionalwalls in Figs. 3 and 4, the fly-wheel is shown seas possible should be used, care being taken cured to a shaft 5 and asbeing of the same not to make the space between the walls so general form as the fly-wheel shown in small as to cause the liquid to be positively Figs. 1 and 2, this beingindicated by the held against movement between them, use of the same reference characters to rewhich would of course impair the efliciency fer to the same parts in both embodiments of the fly-wheel as a means for damping out of the invention which are illustrated. In fluctuations. A space of about one-sixteenth the fly-wheel shown in Figs..3 and 4, howof an inch has been found to be satisfacever, the sectional walls in the chamber tory when mercury is employed. Another formed by the hollow rim portion, infactor which alfects the efliciency of the flystead of being radial are concentric with wheel as a damping device is the viscosity the axis of the wheel. As shown, said walls of the liquid employed. For this reason, an consist of hollow cylinders 24 which are amalgam of mercury and some metal such concentrically arranged and are held apart as cadmium may be used for the purpose of by spacing rings 25 arranged at each end of obtaining a greater damping elfect than is the chamber. A liquid, such as mercury, obtained by the use of pure mercury. may be introduced into the ehamberthrough What is claimed is: openings in the shell 133, closed by plugs 26. 1. A fly-wheel having a unitary chamber he partitions 24 are either made to fit the containing a liquid and sectional walls subchamber loosely or are provided with perfostantially parallel to the path of movement rations 27 which permit the chamber to be of said chamber. readily filled by the liquid. 2. A fly-wheel having concentric with its It is evident that, in either the fly-wheel -axis a unitary chamber containing a liquid shown in Figs. 1 and 2 or the fly-wheel and sectional walls arranged substantially shown in Figs. 3 and 4, the sectional walls parallel to the path of movement of said in the chamber formed by the hollow rim chamber.

' are substantially parallel to the path of 3. A fiy-wheel having a hollow rim pormovement of said chamber, that they pretion containing a liquid and sectional walls sent a large surface with which the liquid partially dividing said rim portion and arcan engage and that they do not divide the ranged substantially parallel to the path of chamber into completely separated sections. movement thereof. The result of this arrangement is that the 4. A fly-wheel having concentric with its area of frictional contact between the liquid axis a chamber containing a liquid and anand the body of the fly-wheel is made very nular sectional walls extending radially in large without, however, positively impeding said chamber.

the mercury in the direction in which it 5. A fly-wheel having concentric with its tends to flow as fluctuations in the speed of axis a chamber containing a liquid, a pluthe fly-wheel take place and that, in assemrality of flat rings, and means for maintainblmg, the varlous sections may be readily ing said rings separated from one another filled with the damping fluid. It has been to form radial sectional walls in said chamfound that this form of flv-wheel is highly her. efiicient as a means for damping out fluctua- In witnem whereof. I hereunto subscribe t1ons m the speed of ashaft to which it is my name this 20th day of March, A. D, applled. Generally speaking, it is advan- 1915.

tageous to make the ratio of the moment of HAROLD WILLIAM NICHOLS.

inertia of the mercury to the moment of initnessesr ertia of the body of the fly-wheel and the E. Evans, parts rotating with it as large as possible; K. L. STAm. 

